215120455400021 has 2 divisors, whose sum is σ = 215120455400022. Its totient is φ = 215120455400020.

The previous prime is 215120455399931. The next prime is 215120455400033. The reversal of 215120455400021 is 120004554021512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160186713807121 + 54933741592900 = 12656489^2 + 7411730^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-215120455400021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215120455400041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107560227700010 + 107560227700011.

It is an arithmetic number, because the mean of its divisors is an integer number (107560227700011).

Almost surely, 2^{215120455400021} is an apocalyptic number.

It is an amenable number.

215120455400021 is a deficient number, since it is larger than the sum of its proper divisors (1).

215120455400021 is an equidigital number, since it uses as much as digits as its factorization.

215120455400021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16000, while the sum is 32.

The spelling of 215120455400021 in words is "two hundred fifteen trillion, one hundred twenty billion, four hundred fifty-five million, four hundred thousand, twenty-one".